JPH08503172A - Method for removing excess lens molding material - Google Patents

Method for removing excess lens molding material

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Publication number
JPH08503172A
JPH08503172A JP6511258A JP51125894A JPH08503172A JP H08503172 A JPH08503172 A JP H08503172A JP 6511258 A JP6511258 A JP 6511258A JP 51125894 A JP51125894 A JP 51125894A JP H08503172 A JPH08503172 A JP H08503172A
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Japan
Prior art keywords
mold half
cavity
contact lens
lens molding
molding surface
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JP6511258A
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Japanese (ja)
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JP3284224B2 (en
Inventor
ソイエ，ポール・ジェイ
ロシェーク，サミュエル
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ウエズレー−ジェッセン・コーポレーション
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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C33/00—Moulds or cores; Details thereof or accessories therefor
    • B29C33/10—Moulds or cores; Details thereof or accessories therefor with incorporated venting means
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C33/00—Moulds or cores; Details thereof or accessories therefor
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C33/00—Moulds or cores; Details thereof or accessories therefor
    • B29C33/0055—Moulds or cores; Details thereof or accessories therefor with incorporated overflow cavities
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C43/00—Compression moulding, i.e. applying external pressure to flow the moulding material; Apparatus therefor
    • B29C43/32—Component parts, details or accessories; Auxiliary operations
    • B29C43/36—Moulds for making articles of definite length, i.e. discrete articles
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C43/00—Compression moulding, i.e. applying external pressure to flow the moulding material; Apparatus therefor
    • B29C43/32—Component parts, details or accessories; Auxiliary operations
    • B29C43/36—Moulds for making articles of definite length, i.e. discrete articles
    • B29C43/38—Moulds for making articles of definite length, i.e. discrete articles with means to avoid flashes
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29D—PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE
    • B29D11/00—Producing optical elements, e.g. lenses or prisms
    • B29D11/00009—Production of simple or compound lenses
    • B29D11/00038—Production of contact lenses
    • B29D11/00057—Production of contact lenses characterised by the shape or surface condition of the edge, e.g. flashless, burrless, smooth
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29L—INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES
    • B29L2011/00—Optical elements, e.g. lenses, prisms
    • B29L2011/0016—Lenses
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S425/00—Plastic article or earthenware shaping or treating: apparatus
    • Y10S425/808—Lens mold
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S425/00—Plastic article or earthenware shaping or treating: apparatus
    • Y10S425/812—Venting

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Health & Medical Sciences (AREA)
  • Manufacturing & Machinery (AREA)
  • Ophthalmology & Optometry (AREA)
  • Eyeglasses (AREA)
  • Moulds For Moulding Plastics Or The Like (AREA)
  • Casting Or Compression Moulding Of Plastics Or The Like (AREA)
  • Processing And Handling Of Plastics And Other Materials For Molding In General (AREA)

Abstract

Process and apparatus for molding the front and rear surfaces of a contact lens in one step is disclosed. Two mold halves matable to form a contact-lens-shaped cavity and a cavity for excess lens forming material surrounding the cavity are provided. The improvement comprises providing the cavity for excess lens forming material with at least two openings and producing differential gas pressure across the openings to remove excess lens forming material.

Description

【発明の詳細な説明】 レンズ成形材料余剰分除去方法 発明の背景 本発明は、レンズの表裏両面を一工程で成形するコンタクトレンズの製造方法 に関する。この成形には周知の如く二個の金型半体が用いられる。第一の金型半 体は凸形のレンズ成形面を、第二の金型半体は凹形のレンズ成形面を有する。そ して、凹形のレンズ成形面にはコンタクトレンズの製造に適した単体のモノマー やモノマーの混合物等のコンタクトレンズ成形材料が盛られる。二個の金型半体 が合体すると、レンズ成形材料が充填されたコンタクトレンズ形のキャビティが 凸形のレンズ成形面と凹形のレンズ成形面との間に形成される。その後、レンズ 成形材料が硬化、即ち、重合するとコンタクトレンズが完成する。 コンタクトレンズ成形用キャビティ内にレンズ成形材料を完全に充填するには 材料を多めに用意する必要がある。当然、余剰分は二個の金型半体が合体した時 にレンズ成形キャビティの外にはみ出してしまう。この余剰分はキャビティ内の 材料と同様に硬化処理中に固化する。所謂、フラッシュである。固化した余剰材 料であるフラッシュは、キャビティの外側に存在する重合抑制剤である空気と接 触するため、硬化後のレンズよりも柔らかく、又、粘性も高くなる。 このフラッシュは、成形後のレンズに粘着すると、非常に厄介である。フラッ シュが粘着したレンズは使いものにならない。そこで、従来から、レンズ成形キ ャビティの周囲に環状のキャビティを形成してフラッシュを処分していたが、フ ラッシュ処理用のキャビティを形成したとしても、フラッシュは依然厄介である ことにかわりない。 ハミルトン等の英国特願第２２２６２７２Ａ号にはフラッシュ処理用キャビテ ィの底部に開口を形成してレンズ成形材料の余剰分を排出する技術が開示されて いるが、レンズ成形材料の余剰分は、小さな開口から重力でもって簡単に流し出 せる程十分な量ではない。又、レンズ成形材料は、金型の製造材料に対する濡れ 性のために重力を利用して効率よく除去するのは難しい。 発明の要約 本発明は、フラッシュ処理用キャビティに二つの開口を形成すると共に、それ らの開口間に差圧を生ぜしめて成形材料の余剰分をフラッシュ処理用キャビティ から文字通りに吸い出したり、吹き出すことによってレンズ成形材料の余剰分を 除去する方法及び装置を提供する。本発明を実施すると、レンズにフラッシュが 殆ど付着しないことから、レンズ成形材料の余剰分を従来方法に比べてはるかに 効果的に除去できる。 図面の説明 図１は、本発明を実施する金型半体を示す図で、その凹形のレンズ成形面には コンタクトレンズ成形材料が盛られている。又、同図は差圧を生ぜしめる好適例 を例示する。 図２は、図１の金型半体が合体してコンタクトレンズ形のキャビティ及び環状 のキャビティが画成された状態を示す図で、コンタクトレンズ形のキャビティ内 にはレンズ成形材料が充填され、環状のキャビティにはその余剰分が流入してい る。 図３は、図１及び図２の装置においてコンタクトレンズ成形材料が硬化処理さ れた後の状態を示す図。 図４は、本発明を実施できる金型半体の別実施例を示す図。 図５は、図４の金型半体が合体してコンタクトレンズ形のキャビティ及びフラ ッシュ処理用キャビティが画成された状態を示す図。 図６は、図１、図２及び図３に示されている金型半体を真空引きする装置を示 す別実施例の図。 図１乃至図５は断面図で、各断面図を軸２５を中心として１８０度回転させる と装置が立体的になる。 発明の詳細な説明 金型半体の構成や形状は、レンズ成形材料の余剰分を排出するための空間に二 つ開口が形成されてさえいれば、特に重要ではない。よって、当該技術分野で知 られている種々の金型の何れの型式でもよい。コンタクトレンズの成形材料は、 単体のモノマー又はその混合物が適している。その材料は、メタクリル酸メチル やアクリル酸シリコン等の疎水性や、或は、メタクリル酸ヒドロキシエチル、メ タクリル酸、Ｎ−ビニル−２−ピロリドン等の親水性でもよい。レンズ成形用モ ノマーが親水性の場合は、エチレングリコール等の溶剤を混入して、本発明で使 用する材料にするとよい。 本明細書中で使用する「合体した金型半体の外側環境」なる用語は、金型半体 の合体時に形成されるレンズ成形キャビティ及び環状のキャビティの外側空間を 意味する。 図１は本発明を実施する金型半体の好適例を示す図である。第一金型半体１０ は凸形のレンズ成形面１１を、第二金型半体１２は凹形のレンズ成形面１４を有 する。これらの金型半体は、合体すると図２に示すようなコンタクトレンズ形の キャビティ１５を画成する。又、金型半体は合体時に、コンタクトレンズ形のキ ャビティ１５の外側周囲に環状のキャビティ１６も画成する。 本発明の好適実施例において、第一金型半体１０は、凸形のレンズ成形面１１ の軸２５と略々平行に延在する第二構造部１８を有する。図２に示すように、二 個の金型半体が合体すると、第二構造部１８は第一構造部１７の少なくとも一部 を取り囲み、環状のキャビティ１６は第一構造部及び第二構造部の下方に位置す る。図１及び図２において、二つのレンズ成形面の軸は符合しており、それらの 軸は一つの参照番号２５で示されている。勿論、使用するレンズに応じてそれら の軸をずらしてもよいが、斯かる構成も又、本発明の範囲内である。 環状のキャビティ１６は、合体した金型半体の外側環境と連通する二つの開口 を有する。図２に示す好適実施例では、第一開口は、第一構造部１７と第二構造 部１８との間に形成された環状の間隙１９であり、第二開口は、第二金型半体１ ２の好ましくは環状のキャビティ１６の底部又はその近傍に形成された穴２０で ある。開口は、当然ながら、コンタクトレンズ形のキャビティの内部に達しては ならない。 環状のキャビティの二つの開口は別の方法で形成することもできる。それらは 例えば金型半体に成形してもよい。開口の一つは二つの金型半体が合体した時に 双方の金型半体間に形成した例えば環状の間隙１９でもよい。開口はレーザ、ド リル、のこぎり等で穿設することができるが、開口の形成方法は特に重要ではな い。 更に、環状のキャビティの開口間に差圧を発生させる手段が設けられている。 差圧は、一方の開口を真空引きし、他方の開口を大気に連通させることによって 発生させることができる。又、加圧ガスを一方の開口内に送給する一方、他方の 開口を大気に連通させてもよい。レンズ成形材料の余剰分を除去する差圧を開口 に発生させる構成は任意でよい。 差圧発生手段の好適例は図１及び図２に図示されている。第二金型半体１２は 支持台２３上に設置される。支持台２３は真空源に連結し、環状の突起２２を有 する。そして、この突起２２を取り囲むように、ゴム等可撓性の材料を素材とす るＯリング２１が取り付けられている。したがって、Ｏリング２１と第二金型半 体１２とは気密関係にある。Ｏリング２１は穴２０を閉塞しない位置にある。環 状の突起２２内の開口２４は周知の真空源に連結する。 図１及び図２の装置は以下の如く作用する。コンタクトレンズ形のキャビティ １５を充填するために必要な量以上の多めの量のレンズ成形材料３０を凹形のレ ンズ成形面１４上に盛る。次いで、金型半体を合体させてコンタクトレンズ形の キャビティ１５と環状のキャビティ１６を画成する。この時、キャビティ１５に はレンズ成形材料が充填され、キャビティ１６には余剰分のレンズ成形材料が流 入する。そして、キャビティ１５内のレンズ成形材料を硬化させる前に、開口２ ４内を穴２０を介して矢印Ｖで示す方向に真空引きする。この真空引きによって 開口１９と開口２０との間に差圧を発生させて環状のキャビティからレンズ成形 材料の余剰分を吸い出す。 レンズ成形材料の余剰分を除去し終えると、キャビティ１５内のレンズ成形材 料を周知の手段によって硬化させる。但し、硬化方法は本発明の要部を構成しな い。硬化方法には、例えば金型半体を加熱する方法、紫外線に曝す方法等適宜の 硬化方法を採用できる。 硬化処理が終了すると、金型半体を開いてコンタクトレンズを取り出す。図３ は開いた状態の金型半体及び本発明の方法によって製造したコンタクトレンズ２ ７を示す。 第一構造部１７と第二構造部１８の間に形成される開口１９の幅は、レンズ成 形材料の余剰分が加圧又は減圧した時に効果的に流出する程度であればよいが、 約０．６ミリが好ましい。又、開口２０の径はレンズ成形材料の余剰分を効果的 に除去できる程度であればいいが、約１．６ミリが好ましい。開口の数や径の大 きさ、及び（減圧や加圧による）差圧の程度によってレンズ成形材料の余剰分の 除去速度が決まる。上述の径でもって、水銀柱で約５６センチの負圧を発生させ ると、レンズ成形材料の余剰分が約２〜３分で効率よく取り除かれる。 図４及び図５は、好適度において上記実施例程ではないが、本発明の別実施例 に係る装置を示す図である。この実施例では、第一金型半体１１０及び第二金型 半体１２０が用いられる。これらの金型半体が合体すると、第一構造部１１７と 第二構造部１１８との間には環状のキャビティである間隙１１９が画成される。 本実施例では、開口は三つ以上設けられる。第一開口１２１は弾性のカップ１３ ０に取り付けられ、一方、そのカップ１３０には圧カホース１３１が連結されて いる。又、第二開口１３２及び第三開口１３３が環状のキャビティに形成されて いる。レンズ成形材料は、空気等の加圧ガスをホースから穴１２１に送り込み、 環状のキャビティ１１９を通過させて、その後、開口１３２及び開口１３３から 送り出すと、取り除かれる。 図６は、図１、図２及び図３の金型半体を真空引きする装置を示す図である。 図６において、三角フラスコ１００はゴム製のシール部材１０１を支持する。一 方、シール部材１０１は金型半体１０及び金型半体１２を支持する。そして、合 体した金型半体の底部が開口１０２を介して真空引きされる。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a contact lens in which both front and back surfaces of a lens are molded in one step. As is well known, two mold halves are used for this molding. The first mold half has a convex lens molding surface and the second mold half has a concave lens molding surface. The contact lens molding material such as a single monomer or a mixture of monomers suitable for manufacturing a contact lens is placed on the concave lens molding surface. When the two mold halves are combined, a contact lens shaped cavity filled with lens molding material is formed between the convex lens molding surface and the concave lens molding surface. After that, when the lens molding material is cured, that is, polymerized, the contact lens is completed. To completely fill the lens molding material into the contact lens molding cavity, it is necessary to prepare a large amount of material. As a matter of course, the surplus portion overflows the lens molding cavity when the two mold halves are combined. This excess, like the material in the cavity, solidifies during the curing process. It is a so-called flash. Since the flash, which is the solidified excess material, comes into contact with air, which is a polymerization inhibitor, existing outside the cavity, it is softer and more viscous than the cured lens. This flash is very troublesome if it sticks to the molded lens. A lens with a sticky flash is useless. Therefore, conventionally, an annular cavity is formed around the lens molding cavity to dispose of the flash, but even if a cavity for flash processing is formed, the flash is still troublesome. British Patent Application No. 2226272A to Hamilton et al. Discloses a technique for forming an opening at the bottom of a flash treatment cavity to discharge the excess lens molding material, but the excess lens molding material has a small opening. Is not enough to easily drain by gravity. Further, it is difficult to efficiently remove the lens molding material by utilizing gravity due to the wettability of the mold with the manufacturing material. SUMMARY OF THE INVENTION The present invention provides a lens by forming two openings in a flashing cavity and creating a differential pressure between the openings to literally suck or blow excess molding material from the flashing cavity. Provided is a method and apparatus for removing a surplus of molding material. When the present invention is carried out, since the flash hardly adheres to the lens, the surplus of the lens molding material can be removed much more effectively than the conventional method. DESCRIPTION OF THE DRAWINGS FIG. 1 is a view showing a mold half for carrying out the present invention, in which a contact lens molding material is placed on the concave lens molding surface. In addition, the same figure illustrates a preferred example that produces a differential pressure. FIG. 2 is a view showing a state where the mold halves of FIG. 1 are united to define a contact lens-shaped cavity and an annular cavity, and the contact lens-shaped cavity is filled with a lens molding material. The surplus is flowing into the annular cavity. FIG. 3 is a view showing a state after the contact lens molding material is cured in the apparatus shown in FIGS. 1 and 2. FIG. 4 is a view showing another embodiment of a mold half body in which the present invention can be carried out. 5 is a view showing a state in which the mold halves of FIG. 4 are united to define a contact lens-shaped cavity and a flash treatment cavity. FIG. 6 is a view of another embodiment showing an apparatus for vacuuming the mold halves shown in FIGS. 1, 2 and 3. 1 to 5 are sectional views, and when each sectional view is rotated 180 degrees about the axis 25, the apparatus becomes three-dimensional. DETAILED DESCRIPTION OF THE INVENTION The configuration and shape of the mold halves are not particularly important as long as two openings are formed in the space for discharging the excess lens molding material. Therefore, any type of various molds known in the art may be used. As a molding material for the contact lens, a single monomer or a mixture thereof is suitable. The material may be hydrophobic such as methyl methacrylate and silicon acrylate, or hydrophilic such as hydroxyethyl methacrylate, methacrylic acid and N-vinyl-2-pyrrolidone. When the lens-forming monomer is hydrophilic, it is advisable to mix a solvent such as ethylene glycol into the material used in the present invention. As used herein, the term "outer environment of the combined mold halves" means the outer space of the lens forming cavity and the annular cavity formed during the combining of the mold halves. FIG. 1 is a diagram showing a preferred example of a mold half for carrying out the present invention. The first mold half 10 has a convex lens molding surface 11 and the second mold half 12 has a concave lens molding surface 14. These mold halves, when combined, define a contact lens shaped cavity 15 as shown in FIG. The mold halves also define an annular cavity 16 around the outside of the contact lens shaped cavity 15 when assembled. In the preferred embodiment of the invention, the first mold half 10 has a second structural portion 18 which extends substantially parallel to the axis 25 of the convex lens molding surface 11. As shown in FIG. 2, when the two mold halves are united, the second structure portion 18 surrounds at least a part of the first structure portion 17, and the annular cavity 16 forms the first structure portion and the second structure portion. Located below. In FIGS. 1 and 2, the axes of the two lens molding surfaces are coincident, and these axes are designated by the single reference numeral 25. Of course, those axes may be shifted depending on the lens used, but such a configuration is also within the scope of the present invention. The annular cavity 16 has two openings that communicate with the outer environment of the combined mold halves. In the preferred embodiment shown in FIG. 2, the first opening is an annular gap 19 formed between the first structure portion 17 and the second structure portion 18, and the second opening is the second mold half. 12 is a hole 20 formed at or near the bottom of the preferably annular cavity 16. The aperture, of course, should not reach the interior of the contact lens shaped cavity. The two openings of the annular cavity can also be formed in different ways. They may be molded into mold halves, for example. One of the openings may be, for example, an annular gap 19 formed between the two mold halves when the two mold halves are joined together. The opening can be formed with a laser, a drill, a saw, or the like, but the method of forming the opening is not particularly important. Further, means for generating a differential pressure is provided between the openings of the annular cavity. The differential pressure can be generated by evacuating one opening and communicating the other opening with the atmosphere. Also, the pressurized gas may be fed into one opening while the other opening is communicated with the atmosphere. Any configuration may be used to generate a differential pressure in the opening that removes an excess of the lens molding material. A preferred example of the differential pressure generating means is shown in FIGS. The second mold half 12 is installed on the support base 23. The support 23 is connected to a vacuum source and has an annular protrusion 22. An O-ring 21 made of a flexible material such as rubber is attached so as to surround the protrusion 22. Therefore, the O-ring 21 and the second mold half body 12 have an airtight relationship. The O-ring 21 is in a position that does not close the hole 20. The opening 24 in the annular protrusion 22 connects to a well-known vacuum source. The device of FIGS. 1 and 2 operates as follows. A larger amount of lens molding material 30 than the amount required to fill the contact lens shaped cavity 15 is placed on the concave lens molding surface 14. The mold halves are then assembled to define a contact lens shaped cavity 15 and an annular cavity 16. At this time, the cavity 15 is filled with the lens molding material, and the excess lens molding material flows into the cavity 16. Then, before the lens molding material in the cavity 15 is cured, the inside of the opening 24 is evacuated through the hole 20 in the direction indicated by the arrow V. By this vacuuming, a differential pressure is generated between the opening 19 and the opening 20, and the surplus portion of the lens molding material is sucked out from the annular cavity. When the excess of the lens molding material has been removed, the lens molding material in the cavity 15 is hardened by a known means. However, the curing method does not constitute an essential part of the present invention. As a curing method, for example, a method of heating a mold half, a method of exposing to a UV ray, and other appropriate curing methods can be adopted. When the curing process is complete, the mold halves are opened and the contact lens is removed. FIG. 3 shows the mold halves in the open position and the contact lens 27 produced by the method of the present invention. The width of the opening 19 formed between the first structure portion 17 and the second structure portion 18 may be such that the excess amount of the lens molding material effectively flows out when pressure or pressure is reduced, but it is about 0. 0.6 mm is preferred. The diameter of the opening 20 may be such that the surplus of the lens molding material can be effectively removed, but is preferably about 1.6 mm. The removal rate of the surplus of the lens molding material is determined by the number of openings, the size of the diameter, and the degree of the pressure difference (due to pressure reduction or pressure application). When a negative pressure of about 56 cm is generated by the column of mercury with the above-mentioned diameter, the surplus of the lens molding material is efficiently removed in about 2 to 3 minutes. 4 and 5 are diagrams showing an apparatus according to another embodiment of the present invention, although the degree of suitability is not as high as the above embodiment. In this embodiment, the first mold half 110 and the second mold half 120 are used. When these mold halves are combined, a gap 119, which is an annular cavity, is defined between the first structure portion 117 and the second structure portion 118. In this embodiment, three or more openings are provided. The first opening 121 is attached to the elastic cup 130, while the pressure hose 131 is connected to the cup 130. Also, the second opening 132 and the third opening 133 are formed in an annular cavity. The lens molding material is removed when a pressurized gas such as air is sent from the hose into the hole 121, passes through the annular cavity 119, and then is sent out through the opening 132 and the opening 133. FIG. 6 is a view showing an apparatus for vacuuming the mold halves shown in FIGS. 1, 2 and 3. In FIG. 6, the Erlenmeyer flask 100 supports a rubber seal member 101. On the other hand, the seal member 101 supports the mold half 10 and the mold half 12. Then, the bottom of the combined mold halves is evacuated through the opening 102.

【手続補正書】特許法第１８４条の８ 【提出日】１９９４年９月１６日 【補正内容】 このフラッシュは、成形後のレンズに粘着すると、非常に厄介である。フラッ シュが粘着したレンズは使いものにならない。そこで、従来から、レンズ成形キ ャビティの周囲に環状のキャビティを形成してフラッシュを処分していたが、フ ラッシュ処理用のキャビティを形成したとしても、フラッシュは依然厄介である ことにかわりない。 ハミルトン等の英国特願第２２２６２７２Ａ号にはフラッシュ処理用キャビテ ィの底部に開口を形成してレンズ成形材料の余剰分を排出する技術が開示されて いるが、レンズ成形材料の余剰分は、小さな開口から重力でもって簡単に流し出 せる程十分な量ではない。又、レンズ成形材料は、金型の製造材料に対する濡れ 性のために重力を利用して効率よく除去するのは難しい。 米国特許第４５７５４４３号は、高圧高温下での回転式射出成形法に関し、冷 却液を使ってフラッシュ粉を取り除き、合体した金型の接合面に影響を与えない ようにしている。 又、英国特願第２２３７２４１Ａ号は、成形用キャビティ内を発泡させる発泡 成形法に関する。キャビティ内に通孔を余分に設けることで、充填度が良好にな る 発明の要約 本発明は、フラッシュ処理用キャビティに二つの開口を形成すると共に、それ らの開口間に差圧を生ぜしめて成形材料の余剰分をフラッシュ処理用キャビティ から文字通りに吸い出したり、吹き出すことによってレンズ成形材料の余剰分を 除去する方法及び装置を提供する。本発明を実施すると、レンズにフラッシュが 殆ど付着しないことから、レンズ成形材料の余剰分を従来方法に比べてはるかに 効果的に除去できる。 図面の説明 図１は、本発明を実施する金型半体を示す図で、その凹形のレンズ成形面には コンタクトレンズ成形材料が盛られている。[Procedure amendment] Patent Law Article 184-8 [Submission date] September 16, 1994 [Amendment content] This flash is very troublesome if it sticks to the molded lens. A lens with a sticky flash is useless. Therefore, conventionally, an annular cavity is formed around the lens molding cavity to dispose of the flash, but even if a cavity for flash processing is formed, the flash is still troublesome. British Patent Application No. 2226272A to Hamilton et al. Discloses a technique for forming an opening at the bottom of a flash treatment cavity to discharge the excess lens molding material, but the excess lens molding material has a small opening. Is not enough to easily drain by gravity. Further, it is difficult to efficiently remove the lens molding material by utilizing gravity due to the wettability of the mold with the manufacturing material. U.S. Pat. No. 4,575,443 relates to a rotary injection molding process under high pressure and high temperature, in which a cooling liquid is used to remove flash powder so as not to affect the joining surface of the combined mold. Further, British Patent Application No. 2237241A relates to a foam molding method in which the inside of the molding cavity is foamed. SUMMARY OF THE INVENTION The present invention forms two openings in a flushing cavity and creates a differential pressure between the openings to form a molding material. The present invention provides a method and a device for removing the surplus of the lens molding material by literally sucking or surplusing the surplus of it from the flushing cavity. When the present invention is carried out, since the flash hardly adheres to the lens, the surplus of the lens molding material can be removed much more effectively than the conventional method. DESCRIPTION OF THE DRAWINGS FIG. 1 is a view showing a mold half for carrying out the present invention, in which a contact lens molding material is placed on the concave lens molding surface.

───────────────────────────────────────────────────── フロントページの続き (81)指定国 ＥＰ(ＡＴ，ＢＥ，ＣＨ，ＤＥ， ＤＫ，ＥＳ，ＦＲ，ＧＢ，ＧＲ，ＩＥ，ＩＴ，ＬＵ，Ｍ Ｃ，ＮＬ，ＰＴ，ＳＥ)，ＯＡ(ＢＦ，ＢＪ，ＣＦ，ＣＧ ，ＣＩ，ＣＭ，ＧＡ，ＧＮ，ＭＬ，ＭＲ，ＮＥ，ＳＮ， ＴＤ，ＴＧ)，ＡＵ，ＢＢ，ＢＧ，ＢＲ，ＢＹ，ＣＡ， ＣＺ，ＦＩ，ＨＵ，ＪＰ，ＫＲ，ＫＺ，ＬＫ，ＬＶ，Ｍ Ｇ，ＭＮ，ＭＷ，ＮＯ，ＮＺ，ＰＬ，ＲＯ，ＲＵ，ＳＤ ，ＳＫ，ＵＡ，ＵＺ，ＶＮ (72)発明者 ロシェーク，サミュエル アメリカ合衆国フロリダ州34228，ロング ボート・キー，ガルフ・オブ・メキシコ・ ドライヴ 6817─────────────────────────────────────────────────── ─── Continued front page    (81) Designated countries EP (AT, BE, CH, DE, DK, ES, FR, GB, GR, IE, IT, LU, M C, NL, PT, SE), OA (BF, BJ, CF, CG , CI, CM, GA, GN, ML, MR, NE, SN, TD, TG), AU, BB, BG, BR, BY, CA, CZ, FI, HU, JP, KR, KZ, LK, LV, M G, MN, MW, NO, NZ, PL, RO, RU, SD , SK, UA, UZ, VN (72) Inventor Roshke, Samuel             34228, Florida, United States             Boat Quay, Gulf of Mexico             Drive 6817

Claims (1)

【特許請求の範囲】 １．コンタクトレンズの両面を成形する方法において、 （ａ）凸形のレンズ成形面を有する第一金型半体を用意する段階と、 （ｂ）凹形のレンズ成形面を有し、前記第一金型半体と合体可能で、合体す るとコンタクトレンズ形のキャビティと、コンタクトレンズ形のキャビティを取 り囲み且つ合体した金型半体の外側環境と連通する環状のキャビティとを画成す る第二金型半体を用意する段階と、 （ｃ）前記コンタクトレンズ形のキャビティを充填するに必要な量以上の量 のレンズ成形材料を前記凹形のレンズ成形面上に盛る段階と、 （ｄ）前記第一金型半体と前記第二金型半体を合体させて、コンタクトレン ズ成形材料が充填された前記コンタクトレンズ形のキャビティと、その余剰分が 流入した前記環状のキャビティとを画成する段階と、 （ｅ）前記コンタクトレンズ成形材料を硬化させて前記コンタクトレンズ形 のキャビティ内にコンタクトレンズを成形する段階とから成る方法であって、 （ｆ）前記段階（ｅ）で硬化処理を完了する前に、前記環状のキャビティの 開口間に差圧を発生させて前記環状のキャビティ内から前記レンズ成形材料の余 剰分を略々取り除くことを特徴とする方法。 ２．前記凸形のレンズ成形面及び前記凹形のレンズ成形面は軸を有し、 前記第一金型半体は前記凸形のレンズ成形面の前記軸と略々平行に延在する 第一構造部を有し、 前記第二金型半体は前記凹形のレンズ成形面の前記軸と略々平行に延在する 第二構造部を有し、 前記第一金型半体と前記第二金型半体が合体すると、該第二金型半体が該第 一金型半体の少なくとも一部を取り囲み、前記環状のキャビティは前記第一構造 部及び前記第二構造部の下方に位置し、 前記環状のキャビティの開口の一方が前記第一構造部と前記第二構造部との 間に形成された間隙であり、 他方の開口が前記第二金型半体に形成された穴である請求の範囲第１項に記 載の方法。 ３．前記段階（ｆ）は、前記第二金型半体の前記穴を該第二金型半体の外から真 空引きする請求の範囲第２項に記載の方法。 ４．コンタクトレンズの両面を成形する装置において、 （ａ）凸形のレンズ成形面と、該凸形のレンズ成形面の第一軸と略々平行に 延存する第一構造部とを有する第一金型半体と、 （ｂ）凹形のレンズ成形面と、該凹形のレンズ成形面の第二軸と略々平行に 延存する第二構造部とを有すると共に、前記第一構造部の少なくとも一部を取り 囲むことができ、前記第一金型半体と合体可能で、合体するとコンタクトレンズ 形のキャビティと、該コンタクトレンズ形のキャビティの周囲外側に位置する環 状のキャビティとを画成する第二金型半体と、 （ｃ）前記環状のキャビティに形成され、前記第一金型半体と前記第二金型 半体が合体すると、その周囲の環境と連通する第一開口及び第二開口とを備え、 該第一開口が前記環状のキャビティの底部に形成された穴である装置であって、 前記第二開口は前記第一構造部と前記第二構造部との間に形成された間隙で あることを特徴とする装置。 ５．前記環状のキャビティの前記開口間に差圧を生ぜしめる差圧発生手段を含ん で成る請求の範囲第４項に記載の装置。 ６．前記差圧発生手段は、前記環状のキャビティの底部に形成された穴を封止し た真空源である請求の範囲第５項に記載の装置。 ７．前記第二金型半体を保持すると共に、Ｏリングを保持する突起と、該環状の 突起内に形成され且つ真空源に連結された開口とを有する支持体を含んで成り、 前記Ｏリングは、前記環状のキャビティの底部に形成された前記穴を取り囲んで 前記第二金型半体を密封する請求の範囲第６項に記載の装置。 ８．コンタクトレンズの両面を成形する装置において、 （ａ）凸形のレンズ成形面を有する第一金型半体と、 （ｂ）凹形のレンズ成形面を有し、前記第一金型半体と合体可能で、合体す るとコンタクトレンズ形のキャビティと、該コンタクトレンズ形のキャビティの 周囲外側に位置し、合体した前記金型半体の外側環境に連通する少なくとも二つ の開口を有する環状のキャビティとを画成する第二金型半体と、 （ｃ）前記環状のキャビティの前記開口間に差圧を生ぜしめる手段とを備え ることを特徴とする装置。[Claims] 1. In the method of molding both sides of a contact lens,     (A) preparing a first mold half having a convex lens molding surface;     (B) It has a concave lens molding surface, and can be and can be combined with the first mold half. The contact lens shaped cavity and the contact lens shaped cavity. Encloses and defines an annular cavity that communicates with the outside environment of the combined mold halves Preparing the second mold half,     (C) Amount greater than that required to fill the contact lens shaped cavity Piling lens molding material of the above on the concave lens molding surface,     (D) The first mold half body and the second mold half body are combined to form a contact lens. The contact lens-shaped cavity filled with the molding material and its surplus Defining the inflowing annular cavity;     (E) Forming the contact lens by curing the contact lens molding material Forming a contact lens in the cavity of     (F) before completing the curing process in step (e), A differential pressure is generated between the openings to allow the lens molding material to remain in the annular cavity. A method characterized by almost removing the surplus. 2. The convex lens molding surface and the concave lens molding surface have an axis,     The first mold half extends substantially parallel to the axis of the convex lens molding surface. Having a first structure portion,     The second mold half extends substantially parallel to the axis of the concave lens molding surface. Has a second structure portion,     When the first mold half and the second mold half are united, the second mold half is Enclosing at least a portion of one mold half, the annular cavity being the first structure Located below the part and the second structure part,     One of the openings of the annular cavity of the first structure portion and the second structure portion Is a gap formed between     The other opening is a hole formed in the second mold half body. How to list. 3. In the step (f), the holes of the second mold half are removed from the outside of the second mold half. The method according to claim 2, wherein emptying is performed. 4. In a device that molds both sides of a contact lens,     (A) Convex lens molding surface and substantially parallel to the first axis of the convex lens molding surface A first mold half having an extended first structure portion;     (B) Almost parallel to the concave lens molding surface and the second axis of the concave lens molding surface And a second structure portion that extends and at least a part of the first structure portion is removed. It can be enclosed and can be combined with the first mold half, and when combined it is a contact lens -Shaped cavity and a ring located outside the perimeter of the contact lens-shaped cavity A second mold half defining a cylindrical cavity,     (C) The first mold half and the second mold formed in the annular cavity. When the halves are united, it has a first opening and a second opening that communicate with the surrounding environment, A device, wherein the first opening is a hole formed in the bottom of the annular cavity,     The second opening is a gap formed between the first structure portion and the second structure portion. A device characterized by being. 5. A differential pressure generating means for producing a differential pressure between the openings of the annular cavity, A device according to claim 4 comprising: 6. The differential pressure generating means seals the hole formed at the bottom of the annular cavity. 6. The apparatus according to claim 5, which is a vacuum source. 7. A protrusion for holding the second mold half and an O-ring, and the ring-shaped protrusion. A support having an opening formed in the protrusion and connected to a vacuum source; The O-ring surrounds the hole formed at the bottom of the annular cavity. An apparatus according to claim 6, wherein the second mold half is sealed. 8. In a device that molds both sides of a contact lens,     (A) a first mold half having a convex lens molding surface,     (B) It has a concave lens molding surface, and can be and can be combined with the first mold half. Of the contact lens-shaped cavity and the contact lens-shaped cavity At least two located outside the perimeter and communicating with the outside environment of the combined mold halves A second mold half defining an annular cavity having an opening of,     (C) Means for producing a differential pressure between the openings of the annular cavity A device characterized by the following.
JP51125894A 1992-11-02 1993-11-01 Lens molding material surplus removal method Expired - Fee Related JP3284224B2 (en)

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US07/970,357 1992-11-02
US07/970,357 US5316700A (en) 1992-11-02 1992-11-02 Method and apparatus for removing excess lens forming material
US970,357 1992-11-02
PCT/US1993/010267 WO1994009960A1 (en) 1992-11-02 1993-11-01 Method for removing excess lens forming material

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EP0670766A1 (en) 1995-09-13
KR950704101A (en) 1995-11-17
DE69312083D1 (en) 1997-08-14
CA2148241C (en) 1999-01-19
EP0670766B1 (en) 1997-07-09
DE69312083T2 (en) 1997-10-30
US5316700A (en) 1994-05-31
JP3284224B2 (en) 2002-05-20
AU5451594A (en) 1994-05-24
NZ257754A (en) 1996-08-27
WO1994009960A1 (en) 1994-05-11
HUT73505A (en) 1996-08-28
SG49174A1 (en) 1998-05-18
ES2104190T3 (en) 1997-10-01
CA2148241A1 (en) 1994-05-11
CZ109895A3 (en) 1996-03-13
AU680637B2 (en) 1997-08-07
ATE155065T1 (en) 1997-07-15
KR100316573B1 (en) 2002-10-31
HU9501257D0 (en) 1995-06-28

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